Sheepdogs and Mastiffs
In Eurasia (Asia + Europe) glaciers receded and gave way to fertile forests. Once large dinosaurs had disappeared, stag, wild boar, deer and animals that were the ancestors of today's sheep and goats became more prevalent. Domestication provided both man and dog with a more reliable food source. ‘Pile dwellers’ could then live in somewhat more permanent settlements like those in the "Fertile Crescent" with dog forming a convenient bond with man. These dogs were used for hunting, as well as guarding the developing settlements. As sheep and goats became domesticated so they formed flocks, these guard dogs were adapted as specialty as Livestock Guardians.
The earliest evidence of domestication of sheep is from 9,000 B.C. The evolution of the Livestock Guardian Dogs we know today corresponds to the gradual migration of flocks of domestic sheep and goats across Europe from East Asia both geographically and in time. But this specialized role is only about 4,000 years old. So it appears that it took around 5,000 years for dogs to become selected for their specialized role of Livestock Guardian Dogs for mobs of sheep and goats. Modern DNA evidence backs up this theory which shows that the highest genetic diversity of domesticated wolves was in East Asia [1].
Through the Middle Ages in Europe guardian dogs have been used to guard livestock, such as sheep and goats. The evolution of the herding sheepdogs breeds we know today correlates with the elimination of the wolf and increased land enclosure for production of food and fodder crops.
The Asiatic Mastiff spread across Europe through the early trade routes through Eurasia from the Fertile Crescent during the first millenium BC. So this Asiatic Mastiff became the kind of mastiff depicted in ancient Assyrian sculptures pictured. It was this type of dog that probably became the ancestor of the old Molossian dog, the forebear of the Bandog or Mastiff (English). As only the strongest dogs would have survived such conditions and journeys, these earned the reputation of being some of the finest specimens[1].